They represents a higher additional cost in a building, and will require on going maintenance. Most importantly, shading needs to allow for daylighting to reduce the amount for electric lighting and thereby electric cooling

What is the typical wind intensity throughout the country?

per UBC wind map, the average national wind intensity ranges from 70 to 80 miles per hour

13 psf

Wind acting on a surface will exert pressure, what is this amount?

anywhere from 13-17 pounds per square foot at a height of 30 ft.

Where do the highest wind speeds occur in the US?

On the gulf coast from texas to florida, and on the atlantic coast.

Wind loads increase with height, while at ground level, wind loads decrease to almost zero.

How is wind pressure expressed?

It is expressed in pounds per square foot and varies as the square of the wind velocity in miles per hour.

When wind velocity doubles, the wind pressure increases fourfold.

What considerations must be taken in regards to winds and building walls?

Building walls must be designed to withstand wind loads, as well as prevent wind infiltration.

Wind infiltration mitigation is the single most important consideration in sustainable design. Cold and warm winds can transfer through walls.

As wind intensity in the area and building height increase, the cost for a building structural system will increase.

Winter winds should always be blocked as much as possible.

Cooling summer winds should be admitted and utilized as much as possible.

Wind breaks can be used to block undesirable winds.

When is the use of a wind break most effective?

In protecting large downwind areas.

What wind conditions will form on tall buildings?

Wind will go over the top of tall buildings

Wind will also blow down the face of the windward side creating a vortex at the ground level

Ground level opening in tall building structures can result in high wind velocities at the ground level.

What are desirable effects of windows?

They allow for views, light, air, and solar radiation.

Light and view are vital to psychological well being

Most people prefer operable windows, and this is also a desirable sustainable design approach.

Even in tall buildings.

Glass can lose heat up to 20 times greater than an insulated wall. For this reason a buildings glazed area is one of the most critical elements as far as heat gain and loss are concerned.

Large areas of glazing, when properly shaded against direct sunlight, can reduce cooling loads in the summer by reducing the need for lighting which in turn reduces cooling loads.

What is daylighting?

It is a technique in which natural sunlight is combined with dimmed overhead lighting to reduce energy costs and indoor heating loads.

Insulation within a wall helps reduce heat gain and heat loss.

How is the measurement of heat transmission thru a material referenced??

The measure of heat transmission is referred to as the U-Factor, which is the number of BTU per hour that passes through one square foot of wall or roof when the difference between inside and outside air temperature is 1 degree farenheit.

Mechanical systems are designed to provide an inside design temperature of ?

75 degrees, when the outside deign temperature is from 90 to 110 degrees.

Land adjacent water is very desirable.

Bodies of water can be protected by preventing or treating polluting runoff prior to entering a body of water.

Bodies of water can also be protected by preventing development around the shoreline, thereby creating attractive open space.

Shapes of bodies of water should be such that the entire shape can not be determined from the shoreline.

Bodies of water have the best aesthetic effect, when they are lower in elevation than any other point in the immediate area.

Free board is the distance between the water level and the level of the land before water floods out.

Bridges across bodies of water are best placed where the body of water is most narrow to minimize structure, where there is good soil in the banks, and where the banks are higher than the expected highest expected floor line.

When bridge are long and require piers be set into the water, the piers should be set so that their long direction is in the direction of water flow to reduce turbulence, and obstruction of flow.

Water fountains are perceived as a cool element, making it a good focus for war dry climates.

What is the Hydrologic/water Cycle?

It is the concept that all the water on the earth, under the ground, and in the atmosphere is part of one unified system.

There are 4 parts to the water cycle

1. Precipitation

2. Runoff

3. Infiltration

4. Transpiration

What is precipitation?

It is when water in clouds reaches a cold temperature and falls to earth as either snow or rain.

What is Runoff?

After precipitation lands reaches the earth, a small amount of it will run off to streams, rivers, and ultimately into the ocean.

What is Infiltration?

When precipitation reaches the ground, a small portion of it will soak into the ground.

What is Transpiration?

Most of the precipitation is evaporated into the atmosphere directly.

Whenever a site is developed, the amount of runoff will increase. What are contributing factors?

1. Removal of vegetation (transpiration)

2. Replacement of pervious land with impervious surfaces (infiltration)

3. A decrease in the other two processes results in a direct increase of runoff.

What is the reasoning behind Detention ponds?

Rainwater is held in ponds during the rain, and then released at a controlled rate.

The intent of this design approach is that the flow of rain water from the new development will be equal to the runoff from the site prior to development.

There are two ways of dealing with runoff on a developed site.

1. Storm sewer

2. Detention pond

Land development on a large scale can result in flooding.

What is a flood plain?

It is the relatively flat land within which a stream overflow spills onto.

The floodplain elevation for a ten-year period, will be lower than the floodplain elevation for a 100-year period.

It is desirable for building in a flood plain to have an elevation higher than that of the given flood magnitude, either 10 or 100 year.

The best use for lands in a flood plain are open space uses such as recreation and agriculture.

Soils within a stream or flood plain are generally poor and subject to volumetric changes under dry and wet conditions.

The conventional solution to the problem of potential flooding involves the construction of concrete channels.

The amount of water found below ground exceeds the amount of water that is found in lakes, or streams.

What is the Ground water table?

It is the area between the zone of Aeration and the Zone of Saturation.

The ground water table usually follows the flow of the land.

What mitigation must occur when there is a high water table?

Where the ground water table is high, roughly 6 feet below ground, construction excavation must be braced and kept dry through pumping.

Basements must be waterproofed

Subsurfaces structures must be designed to resist hydrostatic pressures

There is also a need to improve the existing poor soil bearing conditions.

What is an Aquifer?

It is an underground permeable material such as sand, gravel, or sandstone.